Receivers for television signals

ABSTRACT

A receiver for television signals is arranged to receive video signals comprising video data and information data. The receiver is arranged to respond to viewer operation of a control device ( 28 ). The receiver includes a processor ( 23 ) for processing selected information data to convert the same into signals representative thereof for output to a television in combination with the video signals. In one mode of operation the decoder responds to manipulation of the control device by causing brief scheduling information pertaining to programmes transmitted in the received signal to be displayed. In another mode of operation the receiver is arranged to display detailed scheduling information pertaining to plural different television signals. The receiver is operable to receive signals containing video data representing a plurality of video clips. The processor is arranged to process the signals and to cause simultaneous display of the clips on a television screen. The processor is arranged to respond to user manipulation of the control device by storing data for subsequent viewing of user selected programmes. The decoder may further comprise a modem ( 32 ) and a CD-ROM drive ( 25   a ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 10/013,683, filed 13 Dec. 2001, now abandoned,which is a divisional application of U.S. patent application Ser. No.08/952,603, filed 23 Apr. 1999, now U.S Pat. No. 6,501,514, which is anational stage filing under 35 U.S.C. §371 of international applicationNo. PCT/GB96/01228, filed 22 May 1996, and claims priority under 35U.S.C. §119 to Great Britain patent application No. 9519651.5 filed 27Sept. 1995 and Great Britain patent application No. 9510429.5 filed 22May 1995.

The invention relates to improvements in receivers for televisionsignals.

BACKGROUND OF THE INVENTION

Originally a television (TV) in a typical home comprised a single unitconnectable to an antenna to receive UHF signals broadcast terrestriallyin different channels each containing a single television programme froma respective television station. More recent advances in technology havemeant that additional equipment, such as video cassette recorders (VCRs)and satellite/cable receiver/decoders (decoders) have become affordableand more widely used. A VCR enables the recording of broadcasts and theplayback of previously recorded cassettes. A decoder enables thereception of additional television programmes broadcast in a relativelylarge number of channels in media using cable or satellite-basedtechnology. Thus, a television system comprising a TV, a VCR and adecoder, enables a user to select for viewing or recording a wide rangeof terrestrial and satellite/cable programmes and to play backpreviously recorded programmes. Such a system therefore enables the userto select a programme for viewing from multiple different media.

As the size of a television system is increased by the addition of extraequipment, control and operation of the system becomes more complex. TheVCR and the decoder can be linked to the TV via its UHF input by tuningthe TV to receive UHF signals from the VCR in one channel and to receiveUHF signals from the decoder in another channel. For this to operatesatisfactorily, the VCR and the decoder must each be tuned to outputsignals in different channels than each other and in channels not usedby terrestrial stations. The VCR and the decoder each contain amodulating circuit for placing the signals onto a UHF carrier so thatthe signals can be demodulated by the receiver within the TV. Suchmodulation and demodulation is undesirable because it results in somedegradation (albeit generally undetectable by the viewer) in theprogramme from the VCR or decoder.

These problems can to some extent be avoided by the use of so-calledSCART connectors between the TV, the VCR and the decoder. The SCARTsystem avoids the unnecessary use of UHF carriers by providing a directpath between the VCR, the decoder and the TV. The SCART system includescontrol lines that enable the VCR to override signals from the TVreceiver, thereby causing the programme from the VCR to be displayed onthe TV screen, and similarly enable the decoder to override signals fromboth the TV receiver and the VCR so that the programme from the decoderis displayed on the TV screen. The use of SCART connectors thussimplifies connection between, and selection of, the TV, the VCR and thedecoder.

However, the SCART system does not overcome the problem of user-friendlycontrol and use of the system. Separate controls (usually in the form ofremote handsets) are provided for each of the TV, the VCR and thedecoder. Recording a satellite/cable programme on the VCR requires theuser to programme the VCR at the required time and to programme thedecoder to switch on to the required satellite/cable programme at therequired time. While this is not difficult for viewers possessed of theappropriate skills, it is too much for a large number of viewers whofind such technology bewildering.

At present most broadcasting, regardless of media, is analog based andcomprises a single television service (e.g. SKY ONE, SKY SPORTS, SKYMOVIES) transmitted on a carrier signal or channel. However, the use ofdigital based broadcast technology is imminent. Digital broadcasttechnology will enable television service companies to transmit in asingle channel high definition television programmes, or pluralprogrammes at conventional definition or multiple customer services, ora combination of these.

In a conventional analogue-based television broadcast system programmes(or “services”) are broadcast by separate television service companieson a single carrier signal (“channel”). In a digital based broadcastsystem it is possible to broadcast plural services multiplexed togetheron a single carrier. Unless the context requires otherwise the term“channel” will be used herein to refer to the bandwidth used by a singleservice to broadcast television programmes or other customer services.The term “channel” therefore encompasses both an entire carrier signal(when the signal is used entirely by a single service) and a portion ofa carrier signal (when the signal is shared by plural services).

The ability to transmit multiple channels in a single carrier signalenables a far greater number of services to be provided in the digitaldomain than is possible in the analogue domain. Some of the channels ina carrier may be used to provide conventional television programmeswhile simultaneously other channels in the carrier are used to providedata for other customer services such as television programme listings,on-line programme ordering or so-called pay-per-view (PPV) services, andso on. Customer services should not be confused with the “services”provided by television companies as discussed hereinabove.

Clearly, as digital broadcasting technology is adopted by the station,the above-discussed problems will increase.

The invention aims to provide a greater degree of integration within atelevision system.

The invention also aims to simplify user control over a televisionsystem. In an embodiment of the invention to be described in greaterdetail hereinbelow, this simplification is achieved by making thecontrol more user friendly by making it more intuitive.

In one aspect the invention provides a remote control device forcontrolling a television system including a plurality of independentlycontrollable units, the device comprising plural user selectable keysand being arranged to response to user selection of a key bytransmitting separate command signals to each of the independentlycontrollable units to cause the television systems to be configured in afirst mode and thereafter responding to further user selection of thekeys by transmitting command signals pertinent to the first mode of thetelevision system.

In another aspect the invention provides a receiver for receivingdigital television signals transmitted in a plurality of channels eachcomprising video data and information data the receiver comprising: adecoder circuit operable on one selected channel for separating in theone channel the information data and the video data and converting thevideo data into signals for output for a television; a store for storinginformation data; a viewer operable control device; and a processorconnected to receive the information data from the decoder circuitand/or the store, the processor being arranged to respond to vieweroperation of the control device by processing selected information datato convert the same into signals representative thereof for output for atelevision in combination with the video signals.

In a further aspect the invention provides a receiver for receivingtelevision signals in a plurality of channels, each signal comprisingvideo data defining a television programme and programme scheduling datadefining the scheduling of programmes in the plurality of channels asscheduling events, the receiver being arranged to produce from areceived television signal output signals defining an image of thetelevision programme and an image of scheduling events for display on atelevision screen, the receiver comprising a user operable selectoroperable to select for display a schedule of events for one channelwhile displaying a television programme in another channel or to selectfor display a television programme in one channel while displaying aschedule of events for the one channel or another channel.

In another aspect the invention provides a receiver for receivingtelevision signals defining television programmes in a plurality ofchannels, the receiver being arranged to produce output signals defininga plurality of video clips representing television programs available inthe plural signal channels which output signals are output for displayof the clips in respective areas on a television screen, the receivercomprising a user operable selector operable to select one of thedisplayed clips and responding to such user selection by storing data tocause the receiver to receive the television signals when the programmeis transmitted in the corresponding channel for display of the programmeon a television screen.

In a further aspect the invention provides a receiver for receivingtelevision signals in a plurality of channels each defining a televisionprogramme and at least a signal in one of the channels furthercomprising programme scheduling data defining events in terms ofchannels, programmes and broadcast times, the receiver being arranged toproduce output signals defining an image of events in the programmeschedule for displaying on a television screen, the receiver comprisinga user operable selector operable to select events identified in thedisplayed programme schedule and responding to such user selection bystoring data to cause the receiver to receive television signalsdefining the programmes in the channels and at the times correspondingto the selected events.

In another aspect the invention provides a receiver for receiving atelevision signal comprising video data defining a video picture andinformation data defining information relating to user selectableservices, the receiver being arranged to produce output signals definingan image representing available services for display on a televisionscreen, the receiver comprising a user operable selector operable toselect a displayed service and a modem responsive to such user selectionfor establishing a connection via a telephone line to a provider of theselected service.

In a further aspect the invention provides a receiver for receiving atelevision signal comprising video data defining a video picture andmessage data defining messages or information to be received by adestination specified by an identity code, the receiver being arrangedto produce output signals defining the video picture for display on atelevision screen, the receiver having a unique identity code and beingarranged to respond to reception of message data having an identity codecorresponding to the unique identity code by producing output signalsrepresenting the message or information in the message data for displayon a television screen.

The above and further features of the invention are set forth withparticularity in the appended claims and together with advantagesthereof will become clearer from consideration of the following detaileddescription of an exemplary embodiment of the invention given withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic diagram of a television receiver system;

FIG. 2 is a functional block diagram of a satellite decoder;

FIG. 3 is a functional diagram showing interaction between hardware andsoftware of the decoder of FIG. 2;

FIG. 4 is a schematic functional diagram of a remote control unit;

FIG. 5 is a schematic diagram of a keypad of the remote control unit;

FIG. 6 is a schematic representation of a screen displayed when changingchannels;

FIG. 7 is a flow diagram representing a “surf” function;

FIG. 8 is a flow diagram representing a “search” function;

FIG. 9 is a schematic representation of an IEPG screen;

FIG. 10 is a schematic representation of a TV Guide screen;

FIG. 11 is a schematic representation of a programme mosaic screen; and

FIG. 12 is a schematic representation of a Box Office screen.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

System Overview

Referring now to FIG. 1 of the accompanying drawings a televisionreceiver system 1 comprises a television (TV), a digital integratedreceiver decoder 3 (decoder) connected to receive signals from asatellite dish antenna 4, and a video cassette recorder 5 (VCR). Thesystem 1 optionally further comprises a personal computer 6 (PC) atelephone/modem 7 and a games console 8 each connected via respectivelines to the decoder 3. SCART connectors or other standard connectorsmay be used as appropriate. The decoder 3 acts as an interface betweenthe TV 2 and the VCR 5, PC 6, modem 7 and games console 8 and thusserves to control the system 1.

FIG. 2 of the accompanying drawings shows the decoder 3 in greaterdetail. The dish antenna receives signals from a satellite (not shown).

Signals from the dish antenna 4 are input to a tuner 12 and from thereto a quadrature phase shift key (QPSK) demodulator 13. Demodulatedsignals are error corrected by way of a forward error corrector circuit14. Data from the forward error corrector circuit is supplied to atransport/demultiplexer 15 which separates the data into video data,audio data, user services data, programme scheduling data, etc. fordistribution to various locations within the decoder. Satellite (andindeed cable) programmes are usually scrambled to prevent unauthorisedaccess by non-authorised subscribers. The decoder 3 therefore comprisesa conditional access control circuit 16 which cooperates with a smartcard 16 a to determine whether the viewer has subscribed to a particularchannel and is therefore authorised to access the channel. Parentalcontrol over channel access is also provided, at least in part, by theaccess control circuit 16. The decoder 3 further comprises adescrambling circuit 17 which is controlled by the access controlcircuit 16 to enable the descrambling of the signal by authorisedsubscribers.

The received signals comprise digitally encoded data. It is envisagedthat the data will be compressed using for example the MPEG 2 standardwhich permits both programme data and additional data (for examplecustomer service data) to be transmitted in a single channel. MPEG 2enables high compression ratios to be achieved.

Descrambled signals from the descrambling circuit 17 are input to avideo decompression and processing circuit 18 and an audio decompressionand processing circuit 19, operating according to the MPEG standard forexample. Decompressed video signals are input to a SCART interface 20for direct input to the TV 2 and to a PAL encoder 21 where they areencoded into the PAL format for modulation by a UHF modulator 22 foroutput to the UHF input of the TV if so desired.

The system 3 is controlled by a processor 23 which communicates with thevarious units of the system via a bus 24. The processor 23 hasassociated with it ROM 25 (optionally including a CD-ROM drive 25 a),RAM 26 (comprising both dynamic RAM and static RAM) and a flash(non-volatile and writable) memory 27. As will be explained in greaterdetail hereinafter the processor 23 controls operation of the decoder 3by controlling the tuner 12 to receive signals for the desired channelfrom the dish antenna 4 and to control demultiplexing, descrambling anddecompression so that the desired programme and/or customer service datais displayed on the screen of the TV 2. Viewer selection of desiredprogrammes and customer services is controlled by way of a remotecontrol unit 28 which in response to viewer manipulation thereoftransmits control signals to a receiver 29 for input to the processor23.

The system 3 further comprises a high-speed data interface 30 and anRS232 interface 31 providing a serial link. The high-speed datainterface 30 and the RS232 interface may be connected to the PC 6 and/orthe games console 8 of FIG. 1. The decoder 3 further comprises a modeminterface 32 for connecting to the telephone/modem 7 of FIG. 1.

Operation of the decoder 3, especially the processor 23, is controlledby software that makes the processor 23 responsive to control signalsfrom the remote control unit 28 and to data included in the signalreceived by the dish antenna 4 and in the memory units 25 to 27. Aschematic representation of the interaction between hardware andsoftware in the decoder 3 is shown in FIG. 3 of the accompanyingdrawings. The data in an incoming signal is separated by the transporter15 into video data and information data. The information data isdistributed around the hardware and software, as will be described ingreater detail hereinafter. The video data and the audio data isdemultiplexed and output in suitable form for supply to a TV by the MPEGvideo and audio circuits 18 and 19. When information is to be displayedeither with or instead of the video, data representing the informationis output in suitable form for supply to the TV via an on-screen driver33 and the video circuit 18. Signals from the OSD driver 33 and thevideo circuit 18 are combined as appropriate before being supplied tothe TV. Operation of the software and hardware of the decoder 3 is basedaround an operating system 35. The conditional access controller 16 hasassociated software which interfaces with the operating system via anapplication translator 36. The processor 23 has its own base operatingsystem 37 which interfaces to the decoder operating system 35 via anapplication translator 38. Applications such as an intelligentelectronic programming guide (IEPG) 39 and other applications 40interface to the operating system 35 via an applications interface 41and associated application translator 42.

The software for applications such as the conditional access 16 and theintelligent electronic programming guide 39 are installed permanentlywithin non-volatile memory, e.g. the ROM 25, of the decoder 3, butvariable information such as new access codes and TV programmescheduling details is updated regularly via signals received from thedish antenna 4. Demodulated signals from the demodulator 13 are input tothe transport portion of the transport demultiplexer 15 which examinesthe data to decide where it should be sent. From time to timesignificant changes may be made to conditional access codes or to themanner in which the intelligent electronic programme guide (IEPG) 39displays programme information. Also, programmes for new applications,say a new banking service for example, may be supplied via the satellitefor the decoder. Such data is routed by the transporter 15 directly tothe conditional access controller 16, the IEPG 39 and areas of the storefor other applications 40.

Operating data 43 is supplied on a substantially continuous basis inevery channel. The operating data 43 includes conditional access data 44associated with a channel and/or programmes therein which enables theconditional access controller 16 to determine whether or not accessshould be allowed to a particular programme by descrambling the datatherefor. Additionally, operating data relating to customer services istransmitted in dedicated channels which will be referred to herein asIEPG channels because they carry control and information data for use bythe IEPG provided by the hardware and software of the processor 23 andthe associated memory devices 25 to 27. Thus, the operating data 43depicted in FIG. 3 also includes IEPG data 45 relating to specificprogrammes and the times at which those programmes will be broadcast,and service information 46 (for example relating to personal bankingservices) and indeed any other data 47 required on a substantiallycontinuous or regular basis for the aforementioned customer services.

The transporter 15 is arranged to supply the operating data 43 to theprocessor 23 via the operating system 35. The processor 23 responds tothe data by sending appropriate commands or information to other unitswithin the system. Control data is also transferred between theprocessor 23 and such units as the demultiplexer 15, the video and audiodecompressors 18, 19, the remote control receiver 29 and the high-speeddata interface 30 via respective drivers 48 to 52.

The combined hardware and software of the decoder 3 enables the data inreceived channels to be decoded for display of viewer selectedprogrammes and customer services. The scrambling is controlled on acontinuous basis and the decoder can be updated with new descramblingcodes as and when required. Data for customer services can also besupplied and updated substantially continuously and programmes relatingto new services and applications can be down loaded into the decoder ifso desired.

Remote Control Unit

Turning now to FIG. 4 of the accompanying drawings, the remote controlunit 28 comprises a keypad 60 which is scanned by a scanner 61. Inresponse to manipulation of a key by the viewer, the scanner 61 outputsa code representing the viewer selected key to a processor 62. Theprocessor 62 has associated with it a memory 63 containing programmedata defining how the processor 62 should respond to codes from thescanner 61. The processor 62 is connected to control a commandtransmitter 64 including for example an infrared light emitting diode(not shown) for transmitting signals to the TV, the decoder 3 and theVCR 5 of the system shown in FIG. 1. Data defining the codes fortransmission by the transmitter are stored in the memory 63. The memory63 includes codes for the vast majority of televisions available in agiven market (e.g. the UK market) and can therefore be said to be a“universal” remote control. Viewer selection of appropriate codes fromthe memory 63 can be made by any one of a large number of well knownmethods and therefore will not be described in further detail herein.

The keys comprising the keypad 60 are shown in greater detail in FIG. 5of the accompanying drawings. For the purpose of simplicity it will beassumed that control over the TV 2 and the decoder 3 only is requiredand that control over the VCR and other units is not required. It will,of course, be appreciated that the principles of operation of the remotecontrol 28 in controlling the TV 2 and the decoder 3 can easily beextended to controlling also the VCR 5 and any other remotelycontrollable apparatus comprising the system 1.

The keypad 60 includes a TV key 65 which causes the remote control tofunction as a controller for the TV 1. When the TV key 65 is pressed theprocessor 62 responds by causing the transmitter 64 to transmit acommand to the decoder to enter a standby mode in which signals are nottransmitted via the SCART interface 20 (i.e. SCART pin 8 to the TV isset low). The transmitter also transmits a command to the TV 2 to selecta predetermined channel, e.g. channel 1. Thus, the system 1 iscontrolled by the remote control unit 28 to operate in a televisionconfiguration in which the television receives terrestrial-basedsignals.

Once the command signals have been transmitted to the TV 2 and thedecoder 3, the processor 62 in the remote control enters a modecorresponding to the television configuration of the system 1. In thetelevision mode the remote control unit 28 responds to viewer operationof keys on the keypad 60 by transmitting command signals exclusively forthe TV 2.

Most, if not all, of the functions of the TV controlled by the variouskeys of the keypad 60 shown in FIG. 5 should be self-apparent, but forthe sake of completeness the following comments will be made. The audiovolume is controlled by a volume control key 66 so-arranged thatpressing the left-hand side thereof reduces the volume of sound outputfrom the TV and pressing the right-hand side increases the volume.Pressing a mute key 67 causes the remote control unit 28 to transmit acommand to mute the sound from the TV. A set of ten numeric keys 68control TV channel selection.

A key 69 carrying the legend “INFO” causes the television to enter ateletext mode when first pressed (assuming the TV has a teletextfacility). Depending on the make and model of the TV, further operationof the key 69 will cause the television to toggle between “TEXT”, “MIX”,and “TV” teletext modes. The teletext mode is exited by pressing a keywith the legend “BACKUP” 70. A set of four coloured keys 71 (red, green,yellow and blue) enable so-called fast-text facilities to be utilisedwith the TV in teletext mode.

Pressing an upwardly pointing key (up key) 72 a causes the TV to step upthrough the channels in the logical order in which they are tuned andpressing the downwardly pointing key (down key) 72 b causes the TV tostep down through the channels. The keypad also includes left and rightkeys 73 a and 73 b that serve no function when the remote control unit28 is operating in the TV mode, but are used together with the up anddown keys 72 a, 72 b to navigate around the IEPG when the system is in asatellite configuration.

The keypad includes an on/off key 74 for causing the TV to switchbetween an on mode and a standby mode. The keypad further comprises a“SAT” key 75, the selection of which causes the remote control unit 28to transmit command signals to the system 1 causing it to operate in asatellite configuration. When the SAT key 75 is pressed the processor 62responds by causing the transmitter 64 to transmit a command to thedecoder 3 to enter a receive mode in which signals are received from thesatellite dish 4, and received signals are decoded and transmitted viathe SCART interface 20 to the TV 2. A command is also sent to the TV 2,if appropriate, so that TV receives signals transmitted by the SCARTinterface 20. If the TV 2 is not connected to the decoder 3 via a SCARTlead, then the commands can be varied to ensure that the TV 2 insteadreceives signals via the UHF modulator 22. Thus the system 1 iscontrolled to operate in a satellite configuration in which the decoder3 receives satellite-based signals which are decoded and output inappropriate form to the TV 2.

Once the command signals have been transmitted to the TV 2 and thedecoder 3, the processor in the remote control enters a satellite modecorresponding to the satellite configuration of the system 1. In thesatellite mode, the remote control unit 28 responds to viewer operationof keys on the keypad 60 by transmitting command signals both to the TV2 and to the decoder 3 as appropriate.

Digital signals in the channels received via the satellite dish 4contain programme schedule information which can be displayed underviewer control on the TV 2 when the system 1 is in the satelliteconfiguration. That is to say, the decoder 3 can be controlled by way ofthe remote control unit 28 to operate as the intelligent electronicprogramme guide (IEPG) by causing the TV to display information relatingto programme schedules, customer services and the like.

The remote control keypad 60 comprises a TV guide key 77, selection ofwhich causes the decoder 3 to output for display a TV guide main menu orscreen. Similarly, selecting a box office key 78, a customer service key79 or an interactive service key 80 will cause the decoder to select anappropriate menu or screen for display to enable viewer interaction. Theprocessor 62 is arranged to respond intelligently to the selection ofany of the keys 77 to 80. If the system 1 (and therefore also the remotecontrol 28) is in TV mode when any of the keys 77 to 80 are depressed,the processor 62 of the remote control responds by transmittingappropriate signals to the TV 2 and the decoder 3 to place the system 1in the satellite configuration. The processor 62 then causes the remotecontrol 28 to enter the satellite mode.

The remote control keypad 60 also includes a select key 81 provided toenable user interaction with IEPG screens displayed on the TV screen.The select key also enables interaction with other information displayedon the TV screen. A help key 82 causes the decoder to output for displayhelp information. The processor 23 is arranged to respond intelligentlyby displaying help information appropriate to the IEPG screen displayedon the TV monitor when the help key 82 is selected. Selection of theinfo key 69 similarly causes the transmission of commands to the decodercausing the decoder processor 23 to output for display appropriateinformation depending on the IEPG menu displayed on the screen of the TV2 when the info key 69 is selected.

When the remote control 28 is operating in the satellite mode, theprocessor 62 therein is arranged to respond to selection of any of thecoloured keys 71 by transmitting so-called quick response commands tothe decoder. The manner in which the decoder responds to the selectionof the coloured keys 71 is software controlled and will vary betweenIEPG screens as will be described in greater detail hereinafter.

Decoder Functions

The decoder 3 provides several facilities based on information stored inthe memory 25 to 27 of the decoder, information transmitted with videoin television channels and information transmitted in dedicated IEPGchannels. The facilities provided by the decoder will be described underseparate headings as follows.

Surf, Search and Scan

It is envisaged that the data in each channel will be in compressedform, for example in accordance with the DVB/MPEG-2 standard. DVB allowsboth video data and other data to be combined in a single channel. Inaddition to the aforementioned operating data 43 (see FIG. 3) for use incontrolling access to channels, the data in a channel can include briefprogramme scheduling data defining the scheduling of programmes inseveral of the channels as scheduling events.

One the scheduling data has been stored in the RAM the informationrelating thereto is available effectively instantaneously for display onthe TV. The scheduling data is transmitted regularly (say every 10seconds) so that the decoders are updated quickly after they areswitched on. The information is brief (e.g. title of programme and itsstart and end times) and only covers a short period of time (e.g. 24 or48 hours) to enable each channel to carry data for other channelsprovided by the same TV service company without excessive overheads interms of bandwidth requirements in each channel and memory requirementsin the decoder.

The decoder is arranged to enable a schedule of events for one channelto be displayed while displaying a television programme in anotherchannel or to display a television programme in one channel whiledisplaying a schedule of events for the one channel or another channel.These facilities (which will be referred to herein as “surf”, “search”and “scan”) allow the viewer to search through the programme schedulinginformation down-loaded from the received signals into the RAM 26 usingthe up and down keys 72 a, 72 b together with the left and right keys 73a, 73 b on the remote control unit 28. The “surf” feature allows theviewer to change channels and to view for the current channel schedulinginformation for the present programme and for the next scheduledprogramme simply by pressing the up and down keys 72 a, 72 b on theremote control keypad 60. The “search” feature allows the viewer to moveforward and backward in time through scheduling information for thecurrent channel. Scheduling information for past programmes is deletedonce the programme has finished. The “scan” feature is a combination ofthe “surf” and “search” features and allows a viewer to view the videofor the current channel while inspecting scheduling information forother channels.

The processor 23 of the decoder is arranged so that the surf mode isentered simply by the viewer pressing the up and down keys 72 a, 72 b.When one of the keys 72 a, 72 b is depressed the decoder responds byselecting another channel and thereafter outputting the video and audiofor that channel to the TV 2. The processor adds information signals tothe video signal so that the screen displayed on the TV 2 is similar tothe screen shown in FIG. 6 of the accompanying drawings. The screendisplayed on the TV comprises a programme portion 95 containing both thevideo for the selected channel and a channel identifier 96 and aninformation portion 97 containing information about the programmecurrently being received including its title and scheduling informationand information about the next programme to be broadcast in the channelincluding its title and scheduling information. Other information suchas the current time and instructions regarding the selection ofprogrammes for other decoder features (e.g. the custom channel to bedescribed in greater detail hereinafter) are also displayed in theinformation portion 97.

The surf feature and the search feature are shown in greater detail inFIG. 7 of the accompanying drawings. First the surf feature. When eitherof the up or down keys 72 a, 72 b are depressed the processor 23 causesthe TV to display the current service picture (say service 1) andinformation relating to that service. This is represented by the box 98in FIG. 7. If no further keys are pressed within the predeterminedperiod, the processor removes the service information from the displayas represented by box 99. If the up key 72 a is depressed the processoris arranged to select the next logical service (i.e. service 2) and tocause the TV to display the picture therefore together with informationrelating thereto as represented by box 100. If the down arrow is insteaddepressed the processor will cause the TV to display the previousservice picture together with information relating thereto asrepresented by box 101. It should be noted that in box 91 service number999 has been identified. This assumes that the decoder is able toreceive 999 different services. The logic of the decoder is such thatwhen the lowest number service is displayed pressing the down buttonwill cause the receiver to select for display the highest number serviceand vice versa. Movement between the boxes 98, 100, 101 and other boxesrelating to other service numbers (not shown) is, of course, controlledby the up and down keys of the remote control 28. In the case of eachbox 98, 100, 101 the information portion for the service is removed sothat only the picture is displayed if no further keys are selected onthe remote control after a predetermined period of time, say tenseconds.

While the information is being displayed the viewer may use the searchfeature by selecting either the left or right key 73 a, 73 b. The rightkey is used to move forward in time, whereas the left key is used totravel backwards. Thus, for example starting at box 98, with service 1picture and service 1 current information displayed on the TV screenselection of the right key 73 b causes the information to change tolater information for service 1 as represented by box 102. The viewermay return to the display represented by box 98 by pressing the left key73 a or may advance the scheduling information to even later informationfor service 1 by again pressing the right key 73 b. Likewise, startingfrom box 100 the viewer can cause the later information for service 2 tobe displayed with the picture for service 2, as represented by box 103,by pressing the right key 73 b. Similar movement through schedulinginformation for other services, e.g. service 999 as represented by boxes101 and 104, is, of course, also possible.

FIG. 8 of the accompanying drawings shows the scan feature in greaterdetail. It will be noted that the left hand column of boxes correspondto the boxes 98 to 101 representing the surf feature in FIG. 7. Startingat box 98 with service 1 picture and service 1 current informationdisplayed on the TV screen, selection of an appropriate key of theremote control unit, e.g. the information key 69 or another dedicatedscan key (not shown). Selection of the information key 69 with theinformation shown in FIG. 6 displayed on the TV screen causes theprocessor to enter the scan function. An appropriate device representingthe scan function may be displayed on the screen if so desired.Selecting the information key 69 again while in the scan function causesexit from the scan function to the normal TV screen represented by box99.

While in the scan mode or function, selecting the left and right keys 73a, 73 b changes the displayed information to earlier or laterinformation for the service currently selected, whereas selecting the upand down keys 72 a, 72 b changes the service for which information isdisplayed. At all times in the scan mode the video for the servicedisplayed when the scan mode was entered (i.e. service 1 picture)remains displayed on the TV screen.

Thus, for example, starting from box 98 and selecting the informationkey 69 followed by the right key 73 b causes the TV to continuedisplaying the picture for service 1 and changes the information toinformation for service 1, as represented by box 105. From box 105,selecting the up key 72 a causes the TV to display the picture forservice 1 together with later information for service 2 as representedby the box 106. If the up key 72 a is again depressed the informationwill change to later information for service 3 (not shown). If, however,starting from box 105 the right hand key 73 b is depressed theinformation displayed will change to even later information for service1 while the picture for service 1 will continue to be displayed, asrepresented by box 107. Starting from box 107 and selecting the up key72 a will result in the processor causing the TV to display service 2even later information together with the service 1 picture asrepresented by box 108.

In other words, while in scan mode selection of the left and right keyscauses the displayed information to move through time and selection ofthe up and down keys causes the displayed information to move throughservices. At all times the picture for the service received when thescan mode was entered (i.e. service 1) will remain displayed on the TVscreen.

A similar logical flow can be developed from other starting points, e.g.box 100 or box 101. The scan mode can be entered from either the surfmode or the search mode by way of the information key 69. If a separatededicated key is provided in the remote control keypad, the processormay be arranged to enter the scan mode directly without first enteringthe surf or search modes.

Intelligent Electronic Programme Guide (IEPG)

The processor 23 in the decoder is arranged to operate in an intelligentelectronic programme guide (IEPG) mode in which information relating toprogramme listings, pay-per-view services, and other customer andinteractive services is displayable on the screen of the TV 2. Thedecoder is arranged to enter the IEPG mode in response to selection ofany one of the TV guide, Box Office, Customer Services or InteractiveServices keys 77 to 80 of the remote control keypad 60. Selection of theTV guide key 77 causes the decoder initially to output data to the TV 2representing an IEPG screen comprising two panels of options 113 and 114as shown in FIG. 9 of the accompanying drawings. The left-hand panel 113contains options corresponding to the keys 77 to 80 on the remotecontrol keypad 60 and it will be noted that the box marked “TV Guide”115 is highlighted as depicted by the double lines surrounding the “TVGuide” legend. In practice the box 115 would be highlighted for exampleby changing the shape and/or size of the box, increasing the brightnessof the box, and/or changing the colour of the box. In the event that theviewer selected one of the other buttons 78 to 80, then thecorresponding one of the other boxes 116 to 118 would instead beinitially highlighted. The boxes 115 to 118 serve as a reminder to theviewer that these facilities are available for selection. The viewer canmove between the boxes by manipulating the keys 77 to 80 on the keypad60 or the up and down keys 72 a, 72 b.

The right-hand panel 114 identifies options available for the IEPGfacility highlighted in the left hand panel 113. Thus, for example whenthe “TV Guide” box 115 is highlighted in the left hand panel, the righthand panel will identify the type of programme listings available in theTV guide.

TV Guide

Programmes can be listed by category, for example time 115, title 116,movies 117, sports 118, childrens 119, factual 120, soaps 121 or hotshows 122. Additionally, a listing of programmes entered into a customchannel 123 (to be described hereinbelow) can be displayed. With the TVguide selected, the viewer may scroll through the available options inthe panel 114 by way of the up and down keys 72 a, 72 b of the remotecontrol unit and may select a listing in a desired format by operationof the select key 81.

When a listing in a desired format is selected, the processor 23 causesthe display to be changed to the TV Guide screen shown in FIG. 10 of theaccompanying drawings. The screen is divided into a top area 125, a gridarea 126, and a lower area 127.

The top area of the TV Guide screen contains information such as a “TVGuide” logo in, say, the top left-hand corner and the current time in,say, the top right-hand corner. A legend indicating the format selected(e.g. “listings by time”) is displayed in the centre of the top area andthe name of the day to which the listings relate is displayed, say, atthe right-hand edge of the top area. The top area 125 also contains anevent icon box 128 which displays graphical icons 129 to 132 indicatingwhether or not an event has subtitles (an ear icon), additionalinformation (an “I” icon), is a pay-per-view event, is subject toparental or other restriction, and so on.

The grid area 126 contains several entries of the selected listing.Entries can be scrolled by way of the up and down keys 72 a, 72 b of theremote control 28. The IEPG is arranged so that at any given time aselected one of the entries displayed in the grid area 126 ishighlighted and the icons in the event icon box 128 relate to thehighlighted entry.

The lower area 127 of the screen displays functions associated with thecolour keys 71 of the remote control. The functions performed inresponses to selection of the colour keys is determined by the IEPGsoftware and will therefore vary between different IEPG screens. Forexample, if the currently displayed listing is “time” the IEPG may bearranged to respond to selection of the red key by changing the screento the “title” listing, and to respond to viewer selection of the greenkey by changing the display to the “movies” listing.

When the “time” listing is selected the IEPG enables the viewer toaccess seven days of listings for all channels. When the “title” listingis selected a list of events for the next 48 hours is displayed inalphabetical order. When the “movies” listing is selected a list ofmovie titles is displayed in alphabetical order. Similarly, when the“sports”, “childrens”, “factual” and “soaps” listings are selectedappropriate lists of programme titles and other information aredisplayed in alphabetical order on the TV screen. When the “hot shows”listing is selected a list of programmes which have been selected by themarketing department of the television service company is displayed inalphabetical order on the screen. Such shows may include firstscreenings, special events and the like that the marketing departmentswish to promote.

The programme information for the listings is carried in a separate IEPGchannel and can therefore be quite detailed. The displayed listing willinclude information about the day on which the programme is being shown,the time at which it starts and the time at which it finishes.

Programme Mosaic

In addition to displaying lists of television programmes available onseveral channels the processor is arranged to display a mosaic ofpromotional video clips simultaneously on the screen of the TV 2. Thehigh bandwidths made available using digital techniques make it bothpossible and cost effective to use a single channel as a promotionalchannels. It is envisaged that the promotional channel would only beaccessible by way of the IEPG to enable viewers to inspect forthcomingpromotions and to select for viewing programmes advertised in the IEPGpromotional channel.

FIG. 11 of the accompanying drawings shows an example of a mosaicdisplay comprising sixteen different promotional video clips running ina respective cell A to P. Each of the promotional video clips is ofrelatively short duration (say 2 to 3 minutes) and is run in acontinuous cycle. The clips are combined in the mosaic form by the TVservice company before transmission, and the whole mosaic is transmittedas video data representing a single picture in a single channel. Dataidentifying the events being promoted in each cell is transmitted withthe video data for use by the processor 23 in the decoder. When themosaic is first displayed one of the cells, e.g. cell F, is highlighted.The processor 23 is arranged to respond to viewer manipulation of the upand down, and left and right keys 72 a, 72 b and 73 a, 73 b of theremote control 28 by changing the highlighted cell. In this way, theviewer is able to navigate about the screen to enable a cell to beselected.

Cell selection is by way of the select key 81. The processor 23 isarranged to respond to manipulation of the select key for example in oneof three ways. One way in which the processor 23 may respond is bytuning the receiver directly to the selected programme so that theviewer may view the programme immediately. Another way in which theprocessor 23 may respond is by adding details of the selected programmeto the custom channel (to be described in greater detail hereinafter).Another way in which the processor may respond is by changing thedisplay to the Box Office format shown in FIG. 12 of the accompanyingdrawings. That is to say, the processor 23 can be arranged so that theprogramme mosaic provides a route into the Box Office facility whichwill now be described.

Box Office (Pay-Per-View)

The Box Office facility may be accessed in several different ways. Oneway, as has already been mentioned herein, is for the viewer to select acell from the promotional programme mosaic. Another way into the BoxOffice facility is for the viewer to select a pay-per-view programmefrom the TV guide.

The main route into the Box Office facility is via the IEPG initialscreen shown in FIG. 9 of the accompanying drawings. With the IEPGinitial screen displayed on the screen of the TV 2, viewer manipulationeither of the box office key 78 or the up, down, left and right keys 72a and b, 73 a and b together with select key 81 of the remote controlunit 28 causes the processor 23 to output for display data in the BoxOffice format shown in FIG. 12. The format of the Box Office screen, andindeed the format of other screens described herein, is defined by theaforementioned template data. The template data may be predefined inmemory or downloaded to the decoder in signals received via thesatellite dish antenna 4.

The box office screen 139 is divided into three areas. The top left handquadrant 140 contains a moving promotional video. In the interest ofbandwidth economy it is preferred that the promotional video is derivedfrom the promotional video in an IEPG mosaic channel. This is achievedby the processor 23 increasing the size of the video clip from the IEPGmosaic channel from 1/16 screen size to ¼ screen size by way of pixelreplication, interpolation, etc. Of course, a separate IEPG channelcontaining only four ¼ size videos could instead be utilized with asuitable number of channels being employed to cover all desiredpay-per-view events, although this is more wasteful of bandwidth. Thetop right hand quadrant 141 contains useful information such as the timeand date and the television service logo.

As has previously been mentioned, each promotional video clip hasassociated with it data defining such information as the title of theprogramme and the time or times when the programme is to be broadcast.The processor uses the received information data together with thetemplate data to generate a title and an event listing which are bothdisplayed in the lower half 142 of the box office screen. Additionalinformation such as special messages or discount information may also beassociated with the promotional video clip. This additional informationmay be displayed in the right hand quadrant 141 or the lower half 142 ofthe box office screen, as desired.

In general the lower half 142 of the screen will display, in addition tothe title and start time (including both time of day and day) of thenext showing, information including at least some of the following. Someprogrammes, especially movies, are shown more than once. The additionalinformation will include the frequency of showing if a programme is tobe shown more than once. The rating of movies will also be shown. Theprice of viewing the programme will be shown in local currency. An “I”symbol will be displayed if an extended description of the programme isavailable. Finally, an ordering message such as “Press SELECT to ordernow” will be displayed in the lower half 142 of the Box Office screen.

As with previously described screens, the processor 23 is arranged torespond to manipulation of the up and down, and left and right keys ofthe remote control unit 28 by moving a highlight, or other suitablemarker such as a cursor, around the Box Office screen.

In the event that the viewer presses the select key on the remotecontrol unit 28, the processor 23 will respond by outputting for displaydata representing a box office ordering screen. The ordering screen isalso displayed if the Box Office facility is entered either from thepromotional mosaic or from the TV Guide. The purpose of the orderingscreen is to enable the viewer to specify in detail the exact programmethat he wishes to order. The ordering screen therefore includes suchinformation as the title of the programme, the start time of theprogramme, or in the case of a movie the next showing of the movie, andthe price of the programme. For movies additional information regardingthe rating and the frequency of showing will also be shown. If adiscount is to be made available for viewing at certain times that toowill be shown. When there is more than one showing of a programme,legends will be displayed for the time of each showing and the viewerwill be able to select the desired showing by way of the up, down, leftand right keys 72 a, 72 b, 73 a, 73 b of the remote control unit 28.

The decoder may include a PIN (Personal Identification Number) facilityto prevent unauthorised ordering of programmes, for example, or theordering of adult rated movies by minors. If a PIN facility is included,the ordering screen will include a portion with which the viewer mustinteract to enter the PIN number via the remote control unit 28 beforethe order can be placed.

Once the viewer is satisfied with the order defined in the order screendisplayed on the TV 2, the viewer may confirm the order by pressing theselect key 81 of the remote control unit. The processor 23 is arrangedto respond to the select command signal from the remote control unit byoutputting data defining a confirmation screen for display on the TV 2.The confirmation screen contains the same information as the orderingscreen together with a message such as “For Final Confirmation PressSELECT”. If any time the viewer wishes to back out of an order or changean order to a different programme instead, pressing the back up key 70will cause the processor 23 to return to displaying of the previousscreen. The viewer pressing the select key 81 of the remote control unitcauses the processor 23 to respond by entering an order placing routine.

If the decoder 3 is connected to a telephone line via the modem 7, theprocessor 23 will send data via the modem 7 to the TV service companyplacing the order for the viewer. The processor 23 is arranged to waitfor confirmation that the order has been accepted, or otherwise, beforecontrolling the modem to hang up. If the order has been accepted theprocessor will output a confirmatory message for display on the TVscreen. If the order is not accepted the processor will instead outputfor display appropriate instructions to the viewer, such as “Pleasecontact the TV service company”.

Where the decoder does not include a modem or where connection cannot bemade via the modem the processor will output for display suitableinstructions to the viewer advising the viewer how to place the order bytelephone.

The CD-ROM drive 25 a can optionally be utilized in order to savebandwidth. Use of the CD-ROM drive 25 a makes it possible for TV servicecompanies to send some data direct to viewers via a compact disc (CD)for insertion into the CD-ROM drive 25 a. The CD may contain templatedata and other similar data associated with the routine operation of theprocessor 23. The CD may also contain data defining a whole month (say)of listings for all services broadcast by the same company, and may evencontain data defining the promotional video clips used in the mosaicdisplay and the Box Office display. Non-changing information such as thetitle of a programme may be delivered to the customer with the videoclip data on CD, and changing information such as future showing timesmay be included in the signals transmitted via satellite.

Alternatively, or additionally, the modem can be utilized in thetransfer of data to viewers. A command signal may be transmitted via thesatellite instructing the processor 23 to cause a message to bedisplayed immediately or when the decoder is next switched on. Themessage would instruct the viewer to connect the modem to a specifiednumber at a specified time for the downloading of new data. Of course,the processor 23 can be arranged to bypass the viewer entirely byresponding to a suitable command signal by causing the modem to connectto the specified number. The approach used to download new or updatingdata is simply a matter of viewer and service company preference.

Custom Channel

The information carried in each channel includes data for the processor23 to enable the decoder 3 to be programmed to switch at appropriatetimes to events selected by the viewer. The processor 23 is thereforeable to create under viewer control a so-called custom channelcomprising a sequence of programmes or events selected in advance by theviewer from the displayed TV guide from the Mosaic or Box Officedisplays or by surfing and searching the brief scheduling informationstored in RAM. In other words, the custom channel is a virtual channelprogrammed by the viewer in accordance with his or her planned viewingschedule.

Data defining the custom channel is held in a look up table in the RAM26. When the viewer selects a programme by pressing the select button 81of the remote control unit a prompt is displayed asking the viewer toconfirm that the programme is to be entered onto the custom channel forfuture viewing. The viewer confirms the selection by pressing the selectkey 81 again.

The titles and other details of programmes in the custom channel can beviewed at any time by selecting the “custom channel” option from the TVlistings display shown in FIG. 6 of the accompanying drawings. Shouldthere be a clash of programmes selected for the custom channel, theviewer is presented with a prompt screen identifying the clash andproviding alternative options. The presentation of programme details onthe custom channel is displayed a day at a time in time order. Theprocessor 23 is arranged to respond to selection of the up and down keys72 a, 72 b by moving through time on the day displayed and to respond toselection of the left and right keys 73 a, 73 b by changing thedisplayed information to previous or subsequent days.

If the custom channel has no events added to it by the viewer then itremains inactive. However, once events have been added to the customchannel by the viewer, operation of the decoder depends on the customchannel. The processor 23 is arranged so that when an event in thecustom channel is one minute away from starting a prompt message isoutput for display on the TV screen reminding the viewer that the eventpreviously selected is about to start. The prompt also asks the viewerfor confirmation that he or she still wishes to tune to the event whenit is scheduled to start. If the viewer presses the select key 81 of theremote control unit the decoder will remain tuned to the current serviceuntil the scheduled start time of the custom channel event, at whichtime the decoder will tune to that event. If the viewer presses thebackup key 70 on the remote control, the prompt will be removed from thedisplay and the decoder will remain tuned to the currently viewedservice. The event will not, however, be removed from the custom channellisting. Consequently, should the viewer choose simply to extend theviewing of the currently viewed event, he can return to thepreprogrammed event at a later time simply by entering the customchannel, for example via the TV guide listing screen shown in FIG. 6. Ifno key is pressed within a predetermined period of time, the prompt isremoved from the display. All entries in the custom channel areautomatically deleted from the RAM once the events have finished.

A programme may be related in some way to other programmes to betransmitted at different times and/or on different channels by the sameTV service company. Obviously, programmes in daily or weekly serials arerelated to each other. Other relationships are less obvious. Forexample, a TV service company may wish to run a season of James Bondmovies over a number of different channels with each movies being shownone or more times. Broadcasting in the digital domain makes it easy toinclude in the data for the showings of each movie further data linkingthat movie to other movies in the season. The processor 23 is arrangedto respond to such linking data by displaying prompts when the viewerselects one movie for the custom channel. The prompts alert the viewerto other movies in the season and ask the viewer whether he/she wishesany of the other movies to be included in the custom channel.Interaction between the viewer and the IEPG then proceeds in a similarmanner to that already discussed hereinabove to allow the viewer to addsome or all of the linked programmes to the custom channel as desired.

Customer Services

The provision of a smart card enables every decoder to be uniquelyidentified. In view of the large data carrying capacity of compresseddigital signals it is therefore possible for a TV service company totransmit personal messages to individual subscribers. In a conventionale-mail system receipt of a message depends on the destination beingconnected to a telephone line. Transmitting e-mail type messages tosatellite decoders with smart cards does not suffer from this weakness.Unless a supply of power is physically removed from a decoder, thedecoder will not normally be switched off. Decoders are designed toenter a stand-by mode when they are switched “off” by the viewer. In thestandby mode a decoder can still receive signals via the satellite dishantenna.

When the user switches “off” the decoder 3, the processor 23 enters astand-by mode in which the information data context of received signalsis monitored for general updating control and programme scheduling dataand also for message data specifically for the decoder 23 as determinedby the identity data in the smart card 16 a. In this way, a simple andinexpensive e-mail type message broadcasting system may be realised. Theinclusion of the modem 32 within the decoder means that communicationfrom the viewer back to the TV service company is also possible.

Interactive Services

The provision of the modem 32 within the decoder 3 also makes viewerinteractive services possible. One application of this is to allowviewers to vote on the progress of a game show by pressing keys of theremote control unit 28. In the interactive mode the processor 23 isarranged to respond to signals from the remote control unit bytransmitting appropriate data to a central polling station via the modem32. Data representing instructions on how to interact with the game(i.e. which keys to press on the remote control unit) and commands tothe processor 23 are transmitted as information data with the videodata. The information data is decoded by the processor 23 which reactsas appropriate to the commands (i.e. connecting the modem to a telephonenumber if the viewer wishes to participate in the game) and also outputsthe game instructions for display with the game programme on the screenof the TV 2.

The modem 32 also makes it possible for a viewer to interact withon-line services such as banking, insurance and mail order. It isenvisaged that a channel similar to the above-discussed mosaic channelwould carry promotional video and other promotional information forseveral companies offering an on-line service. The processor 23 can bearranged to enable the viewer to select a service from a service mosaicdisplay screen in much the same way as programmes can be selected thepromotional mosaic display screen shown in FIG. 11 of the drawings.Viewer selection of a service would result in the processor 23establishing connection with the service via the modem 32.

It can take tens of seconds for a modem to establish connection. Theprocessor is arranged to display the promotional video for the selectedservice together with additional information relating to the service on,say, a screen similar to the box office screen shown in FIG. 12 whilethe modem connection is being made. Such a display entertains the viewerwhile the modem connection is being established and is replaced with amore appropriate screen for interaction with the service once theconnection has been made.

It will be appreciated by those possessed of the appropriate skills andknowledge that the invention is not limited to television signalstransmitted via satellite or cable. The invention can be applied equallyto any system for receiving digital television signals including thedigital signal systems currently under investigation by terrestrialbroadcasters in the UK and elsewhere.

Having thus described the present invention by reference to a preferredembodiment it is to be well understood that the embodiment in questionis exemplary only and that modifications and variations such as willoccur to those possessed of appropriate knowledge and skills may be madewithout departure from the spirit and scope of the invention as setforth in the appended claims and equivalents thereof.

1. A receiver for receiving digital television signals transmitted in aplurality of channels each comprising video data and information datathe receiver comprising: a decoder for separating the information dataand the video data and converting the video data on a selected channelinto signals for output for a television; a store for storinginformation data; a viewer operable control device; and a processorconnected to receive the information data from the decoder circuitand/or the store, the processor being arranged to: respond to vieweroperation of the control device by processing selected information datato convert the same into signals representative thereof for output for atelevision in combination with the video signals, and vary both theselected channel and the selected information data in response to onesaid viewer operation of the control device, and to vary only theselected information data in response to a different said vieweroperation of the control device.
 2. A receiver as claimed in claim 1,wherein the information data is carried in each channel and comprisesprogramme scheduling information for plural channels.
 3. A receiver asclaimed in claim 1, wherein the decoder and the processor are arrangedto respond to said different viewer operation of the control device byvarying the information represented by the output signals to correspondto scheduling information for programs in another channel different fromthe selected channel.
 4. A receiver as claimed in claim 1, wherein theselected information comprises current scheduling information forprogrammes in the selected channel, and the processor is arranged torespond to said different operation by outputting signals representingscheduling information at a different time in the present channel.
 5. Areceiver as claimed in claim 3, wherein the selected informationcomprises current scheduling information for programmes in anotherchannel different than the selected channel, and the processor isarranged to respond to said different operation by outputting signalsrepresenting scheduling information at a different time in the otherchannel.
 6. A receiver as claimed in claim 1, wherein the informationdata comprises detailed programme scheduling information for pluralchannels, which scheduling information data is carried occasionally byeach channel, and the decoder is arranged to store the detailedscheduling data in the store.
 7. A receiver as claimed in claim 6,wherein the processor is arranged to respond to viewer operation of thecontrol device by processing data from the store to derive therefromsignals representing selected detailed information in selected channelsfor output to a television.
 8. A receiver as claimed in claim 7, whereinthe processor is arranged to respond to viewer operation of the controldevice by storing, for a selected programme in the channels, viewingdata to enable the programme to be viewed when video data therefore istransmitted in a channel at a scheduled time.
 9. A receiver as claimedin claim 1, wherein one of the plurality of channels comprises video andinformation data for a plurality of video clips which video clips eachrepresent a respective programme available or to be made available forviewing.
 10. A receiver as claimed in claim 9, wherein the decoder isarranged to output signals representing the plural video clips forsimultaneous display in respective portions of a television screen, andthe processor is arranged to respond to viewer operation of the controldevice by storing for a selected video clip viewing data to enable theprogramme to which the selected clip relates to be viewed when videodata therefore is transmitted in a channel at a scheduled time.
 11. Areceiver as claimed in claim 9, wherein the decoder is arranged torespond to viewer operation of the control device by outputting signalsrepresenting a selected one of the video clips for display on thetelevision screen, and the processor is arranged to respond to saidviewer operation by processing the information data and outputtingsignals representing scheduling information for the selected clip.
 12. Areceiver as claimed in claim 11, wherein the processor is arranged torespond to further viewer operation of the control device by storingviewing data to enable the programme represented by the clip to beviewed when video data therefore is transmitted in a channel at ascheduled time.
 13. A receiver as claimed in claim 8, wherein theprocessor is arranged to store the viewing data in the store in such amanner as to enable custom channel data to be defined, the decoder andthe processor being arranged to operate according to the custom channeldata depending on viewer operation of the control device.
 14. A receiveras claimed in of claim 1, further comprising a modem interface or amodem to enable the processor to transmit and receive signals via atelephone line, the processor being arranged to output signals to themodem for transmission depending on received information data and useroperation of the control device.
 15. A receiver as claimed in claim 1,further comprising an identifying device containing unique identity datato enable the receiver to be uniquely identified, and wherein theinformation data in the channels comprises message data for a receiverof a specified identity, and the processor is arranged to respond to themessage data depending on the identity data in the identifying device bystoring the message data in the store and converting the same intosignals representing a message for output for a television.
 16. Areceiver as claimed in claim 1, wherein the information data comprisesupdating data which is transmitted occasionally for use by theprocessor.
 17. A receiver as claimed in claim 1, further comprising aCD-ROM drive for reading a CD containing updating data for use by theprocessor.
 18. A receiver as claimed in claim 16, wherein said updatingdata comprises data defining new applications to be executed by theprocessor.
 19. A receiver as claimed in claim 16, wherein said updatingdata comprises template data for use by the processor in defining theformat in which information is represented by the signals output for atelevision.
 20. A receiver as claimed in claim 1, wherein the vieweroperable control device comprises a remote control device.
 21. Areceiver as claimed in claim 1 connected to a television.